The rotator cuff is a group of four muscles and their tendons that combine to from a “cuff” around the head of the humerus (the upper end of the arm). These four muscles—supraspinatus, infraspinatus, subscapularis, and teres minor—originate from the scapula (shoulder blade). The rotator cuff stabilizes the humeral head within the joint socket while coordinating the motion of the arm by initiating both lifting and rotation of the arm at the shoulder.
Causes of a Rotator Cuff Tear
There are two main causes of rotator cuff tears: acute injuries and degeneration.
- Falling down on an outstretched arm or lifting something too heavy with a jerking motion.
- Degeneration refers to chronic wear and tear on the tendons in the shoulder joint that occurs in people over 40.
- Repetitive motion and stress from sports, work-related activities, or routine chores can cause overuse tears.
- As a person ages, calcium deposits or bone spurs due to arthritis can irritate or pinch the rotator cuff.
Symptoms and Diagnosis
Symptoms of a rotator cuff tear may include:
- Pain and muscle spasms in the upper arm and shoulder, particularly when resting or lying down.
- Shoulder weakness when lifting or rotating the arm.
- Shoulder pain when movement involves lifting, pulling, or reaching behind the back or overhead.
- Crackling sensation when moving your shoulder in certain positions.
Rotator cuff tears are initially diagnosed based on a physical examination where the patient complains of pain and limited motion in the shoulder and/or weakness and muscle deterioration. Imaging tests help confirm the diagnosis.
X-rays, MRI scans, or ultrasounds can all be used to help diagnose whether a tear to the rotator cuff exists. MRI scans can be useful in confirming the diagnosis by displaying the soft tissue around the shoulder and rotator cuff. Early diagnosis and treatment of a rotator cuff tear may help improve overall treatment results.
The goals of treatment are to improve overall shoulder function and quality of life by relieving pain, improving range of motion, and restoring strength to the involved shoulder. Many rotator cuff tears can be treated non-surgically. Anti-inflammatory medication, steroid injections, and physical therapy may all be of benefit in treating symptoms of a cuff tear. Even though a full-thickness tear cannot heal without surgery, satisfactory function can often be achieved with non-surgical treatments.
Surgery is recommended if pain or weakness in the shoulder that does not improve after six months of non-surgical treatments. Frequently, patients who require surgery will report pain at night and difficulty using the arm for lifting and reaching. Surgery is also indicated in active individuals who use the arm for overhead work or sports. The type of repair performed is based on the findings at surgery. A partial tear may require only a trimming or smoothing procedure called a debridement. A full-thickness tear with the tendon torn from its insertion on the humerus is repaired directly to bone. Three techniques are used for rotator cuff repair:
- open repair (through a traditional incision)
- mini-open repair (partially assisted by a camera view, with a smaller incision)
- arthroscopic (performed with only a small camera inserted through multiple small puncture wounds)
Rehabilitation is important in both the non-surgical and surgical treatments of a rotator cuff tear. Recovery is usually six months or longer depending on the extent of the tear. When a tear occurs, there is a great loss of motion of the shoulder. An exercise or physical therapy program is necessary to regain strength and improve function in the shoulder. Even though surgery repairs the defect in the tendon, the muscles around the arm are still weak. A disciplined rehabilitation regimen is necessary for the procedure to succeed and may take several months.